Drum comprising support mounted grid structure

ABSTRACT

A drum comprising an annular, perforated, rigid support and an annular honeycomb or grid structure mounted circumferentially around the support. The grid structure includes planar strip means extending circumferentially of the support providing the drum with substantial circumferential rigidity; and the support provides the drum with substantial longitudinal stiffness.

United States Patent 1 Pennington DRUM COMPRISING SUPPORT MOUNTEI) GRID STRUCTURE [75] Inventor: Rohe V. Pennington, Rome, Ga.

[73] Assignee: Improved Machinery Inc., Nashua,

22 Filed: Nov. 5, 1971 211 Appl. No.: 195,953

[52] U.S. Cl. 162/357, 29/121 R, 162/368,

162/372, 210/402 [51] Int. Cl. D2lf 1/60 [58] Field of Search 162/357, 368, 372,

[56] References Cited UNITED STATES PATENTS 3,577,315 5/1971 Franklin 162/357 Rich et al. 210/402 Nov. 20, 1973 3,259,961 7/1966 Bryand 29/121 R 3,579,422 5/1971 Minick et a1.. 162/314 3,139,375 6/1964 Bryand 162/372 X 3,564,686 2/1971 Bryand 29/121 R 3,590,453 7/1971 Bryand 210/402 X 3,630,838 12/1971 Bryand 162/372 X Primary ExaminerS. Leon Bashore Assistant ExaminerRichard V. Fisher Att0rneyFrank S. Troidl et al.

[57] ABSTRACT A drum comprising an annular, perforated, rigid support and an annular honeycomb or grid structure mounted circumferentially around the support. The grid structure includes planar strip means extending circumferentially of the support providing the drum with substantial circumferential rigidity; and the support provides the drum with substantial longitudinal stiffness.

10 Claims, 2 Drawing Figures Patented Nov. 20,1973 3,773,614

INVENTOR ROHE l4 PENN/N6 7'0/V ATTORNEY DRUM COMPRISING SUPPORT MOUNTED GRID STRUCTURE The present invention relates to drums formed from annular honeycomb or grid structures such as, for example, employed by the pulp and paper making industry.

Drums of this general type are capable of employment in a wide variety of applications including, by way of illustration, the filtering of slurries and the air drying of paper. Conventionally, these drums sometimes have been constructed from strip material arranged to longitudinally extend length-wise of the drums, but more preferably have been formed from circumferentially wound strip material as this latter construction provides the drums with significantly greater circumferential strength and rigidity. Drums of this latter, more advantageous, construction are, for example, disclosed in U.S. Pat. Nos. 3,105,043 and 3,320,399, both assigned to the assignee of the present invention, which describe drums formed from circumferentially wound, alternately arranged planar and waved strips welded one to the other. The manufacture of such prior drums, however, requires that the welded interconnections of the strips be sufficiently strong and enduring to provide the drums with substantial longitudinal stiffness; and, hence, during the manufacture of these prior drums, difficulties may be encountered in forming the welded interconnections of the strips at a rate sufficiently rapid to produce an economical drum.

The principal object of the present invention is to provide a new and improved drum including honeycomb or grid structure, which drum is particularly constructed and arranged to possess both substantial circumferential rigidity and substantial longitudinal stiffness.

Another object of the invention is to provide a new and improved drum of the type set forth which, although including circumferentially wound strip material, is particularly constructed and arranged to avoid the necessity for reliance on the welded interconnections of the strip material to provide the drum with longitudinal stiffness.

Another object is to provide a new and improved drum of the type set forth which is relatively simple and economical in manufacture.

Further objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein the preferred form of the invention has been given by way of illustration only.

In accordance with the invention, a drum may comprise an annular, rigid support having openings through its thickness and an annular grid structure mounted circumferentially around the support with its inner circumference on the outer circumference of the support, the grid structure including waved strip means extending around the circumference of the support and planar strip means longitudinally extending around the circumference of said support alternately arranged with the waved strip means, and the waved strip means and the planar strip means being interconnected and cooperating to define openings through the grid structure in communication with the openings in the support.

Referring to the drawings:

FIG. 1 is a view in perspective, partially broken away and in section, illustrating one drum embodying the invention; and

FIG. 2 is an enlarged, fragmentary top or plan view of the drum of FIG. 1 showing details of the construction of the grid structure of the drum.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views, the illustrated drum comprises a rigid, cylindrical support or shell 10 perforated to include openings 12 radially through its thickness at spaced locations throughout its length and armate extent. The support 10 is formed from steel or other similar enduring material of significant strength and is of a substantial thickness at the minimum about onesixteenth of an inch. The openings 12 are unrestricted and of relatively large cross-sectional diameter to freely permit fluid flow to-and-from the interior of the support 10, the total cross-sectional area of the openings 12 normally being at least about 20 percent of the outer circumference of the support 10. The ends of the support 10 are closed by end closure plates 14, welded or otherwise affixed to the support 10, which carry integral stub shafts 16 adapted for rotatably mounting the ends of the support 10. As illustrated, the end plates 14 are of diameters substantially greater than the support 10 to have their annular outer circumferences radially outwardly of the outer circumference of the support 10; and one of the stub shafts 16 is hollow and contains a conduit 18 through which fluid may be drained from the interior of the support 10 or supplied to the latter, depending on the particular application in which the drum is employed.

A cylindrical honeycomb or grid structure, shown fragmentarily in the drawings as 20, is mounted around the outer circumference of the support 10 with its inner circumference directly supported by the outer circumference of the latter. As illustrated, the grid structure 20 is, per se, of construction described in the aforementioned U.S. Pat. No. 3,105,043 and includes sheet metal, planar and waved strips 22, 24, respectively, which are helically wound around the support 10 in alternate arrangement throughout the length of the latter. The strips 22, 24 are arranged with their greatest transverse or widthwise dimensions radially of the support 10 and of the grid structure 20; and, as illustrated, are of such transverse dimensions that the outer circumference of the grid structure 20 is aligned with the outer circumferences of the end closure plates 14. The strips 22, 24 cooperate to provide the grid structure 20 with a plurality of therebetween openings 26 generally radially through the thickness of the grid structure 20 in communication with the openings 12- in the support 10, the openings 26 providing the grid structure 20 with a total open area which may be in the range of percent to percent of its total circumferential area. The waved strip 24 is preferably formed to comprise straight parallel connecting portions 28, alternately arranged on the opposite sides of its central plane 30, and diagonal portions 32 extending transversely to such central plane 30 interconnecting the portions 28. However, the portions 28 may, if desired, be formed of truncated triangular construction as described in U.S. Pat. No. 3,105,043.

The inherent longitudinal strength or stiffness of the support 10 provides the aforedescribed drum with significant longitudinal stiffness, thus causing the welds interconnecting the strips 22, 24 to function solely to interconnect the strips and maintaining such welds substantially unstressed during the employment of the drum. The inherent longitudinal rigidity of the circumferentially wound planar strip 22 provides the drum with notable circumferential rigidity.

The drum may be advantageously manufactured by a method of the type described in co-pending U. S. Pat. application Ser. No. 196,074 entitled METHOD OF MAKING ANNULAR GRID STRUCTURE which was filed by Lawrence A. Carlsmith on the filing date of this application. In this event, the support would be employed as the rotatably driven mandrel and, as described in the aforesaid co-pending patent application, the strips 22, 24 would be helically wound around the support 10 in alternate fashion whereby the planar strip 22 is wound tightly around the support 10 and the wound strips cooperate to progressively form an axial build-up of the grid structure around the support 10. Adjacent coils of the strips 22, 24 would be interconnected, such as by welding, during the winding such that the planar strip 22 is during the welding substantially heated at the locations of the welds while tightly wound around the support 10. Then, the heated tightly wound planar strip 22 would be allowed to cool while around the support 10. If desired, the strips 22, 24 may be welded along their inner circumferences to the outer circumference of the support 10.

As will be seen, the drum provided by the invention is capable of employment in a wide variety of applications both in the pulp and paper making industry and elsewhere. For example, with particular reference to the pulp and paper making industry, the drum with a covering circumferential filter screen if the openings 26 be too large to serve as filtering openings or without such covering screen if the openings 26 be sufficiently small to function as filtering openings, is readily employable as a rotatably driven filter drum for filtering a slurry such as, by way of illustration, a pulp suspension or an effluent sludge. In this event, liquid drained from the suspension inwardly through the openings 26, 12 in the grid structure 20 and support 10 would be discharged from the interior of the support 10 through the conduit 18. Also, the drum provided by the invention is capable of employment in the air drying of a paper web passed circumferentially thereover in which event moist air can either be discharged from the interior of the support through the conduit 18 or, alternatively, the drying air can be supplied through such conduit 18 and the interior of the support 10 and communicating openings 12,26. Moreover, if desired, the drum of the invention, either with or without a circumferential cover around the grid structure 20, could be employed as a supporting roll.

It will be understood, however, that, although only a single embodiment of the invention has been illustrated and hereinbefore specifically described, the invention is not limited merely to this single embodiment but rather contemplates other embodiments and variations within the scope of the followingclaims.

Having thus described my invention, 1 claim:

l. A drum comprising an annular, rigid support having openings through its thickness and an annular grid structure mounted circumferentially around said support with its inner circumference directly supported by the outer circumference of said support, said grid structure including waved strip means extending around the circumference of said support and planar strip means longitudinally extending around the circumference of said support alternately arranged with said waved strip means, and said waved strip means and said planar means being interconnected and cooperating to define openings through said grid structure in communication with said openings in said support.

2. A drum according to claim 1, wherein said grid structure consists only of said waved strip means and said planar strip means.

3. A drum according to claim 1, wherein said waved strip means includes alternating generally diagonal segments and therebetween connecting segments on opposite sides of the central plane of said waved strip means, said connecting segments being connected to said planar strip means and said diagonal segments crossing said central plane of said waved strip means.

4. A drum according to claim 1, wherein said grid structure is welded to said support.

5. A drum according to claim 1, further comprising end closure means closing the ends of said support, said end closure means including annular outer peripheries aligned with the outer circumference of said grid structure.

6. A drum according to claim 1, wherein said support is of a radial thickness at least about one-sixteenth of an inch, and the openings in said support provide said support with at least 20 percent open area, and said waved and planar strip means are helically wound around said support.

7. A drum according to claim 1, wherein said grid structure extends throughout the length of said support.

8. A drum according to claim I, wherein said grid structure consists only of said waved strip means and said planar strip means, said support is of a radial thickness at least about one-sixteenth of an inch, the openings in said support provide said support with at least 20 percent open area, and said waved and planar strip means are helically wound around said support, and further comprising end closure means closing the ends of said support, said end closure means including annular outer peripheries aligned with the outer circumference of said grid structure.

9. A drum according to claim 8, wherein said waved strip means includes alternating generally diagonal segments and therebetween connecting segments on opposite sides of the central plane of said waved strip means, said connecting segments being connected to said planar strip means and said diagonal segments crossing said central plane of said waved strip means.

10. A drum according to claim 9, wherein said grid structure extends throughout the length of said support. 

1. A drum comprising an annular, rigid support having openings through its thickness and an annular grid structure mounted circumferentially around said support with its inner circumference directly supported by the outer circumference of said support, said grid structure including waved strip means extending around the circumference of said support and planar strip means longitudinally extending around the circumference of said support alternately arranged with said waved strip means, and said waved strip means and said planar means being interconnected and cooperating to define openings through said grid structure in communication with said openings in said support.
 2. A drum according to claim 1, wherein said grid structure consists only of said waved strip means and said planar strip means.
 3. A drum according to claim 1, wherein said waved strip means includes alternating generally diagonal segments and therebetween connecting segments on opposite sides of the central plane of saId waved strip means, said connecting segments being connected to said planar strip means and said diagonal segments crossing said central plane of said waved strip means.
 4. A drum according to claim 1, wherein said grid structure is welded to said support.
 5. A drum according to claim 1, further comprising end closure means closing the ends of said support, said end closure means including annular outer peripheries aligned with the outer circumference of said grid structure.
 6. A drum according to claim 1, wherein said support is of a radial thickness at least about one-sixteenth of an inch, and the openings in said support provide said support with at least 20 percent open area, and said waved and planar strip means are helically wound around said support.
 7. A drum according to claim 1, wherein said grid structure extends throughout the length of said support.
 8. A drum according to claim 1, wherein said grid structure consists only of said waved strip means and said planar strip means, said support is of a radial thickness at least about one-sixteenth of an inch, the openings in said support provide said support with at least 20 percent open area, and said waved and planar strip means are helically wound around said support, and further comprising end closure means closing the ends of said support, said end closure means including annular outer peripheries aligned with the outer circumference of said grid structure.
 9. A drum according to claim 8, wherein said waved strip means includes alternating generally diagonal segments and therebetween connecting segments on opposite sides of the central plane of said waved strip means, said connecting segments being connected to said planar strip means and said diagonal segments crossing said central plane of said waved strip means.
 10. A drum according to claim 9, wherein said grid structure extends throughout the length of said support. 